Some string follow is not necessarily a bad thing (i.e 2" or less) Normally, self bows are braced at about 6"(sometimes less). measurement from shelf, grip, on belly side. Yes, insufficently dried wood will cause severe string follow. Try making that ash bow long(68-72") and wide (2" at the fades), and of course dry-- You'll likely succeed in making serviceable bow, at the very least.